As a conventional pull-on diaper, a pull-on diaper is known that comprises an outer cover adapted to be worn around the front side and rear side of a wearer, and a crotch portion adapted to be worn along the wearer's crotch, which is arranged between the front side and rear side of the outer cover, wherein an absorbent body is disposed on the crotch portion (for example, see Patent Literatures 1 and 2).
The outer cover has a two-layer structure of an inner layer material and an outer layer material laminated over almost their entire surfaces, and a sheet in which the inner layer material and outer layer material are attached to each other through an interposed elastic element is used to constitute the outer cover. This sheet is divided in two widthwise, and an absorbent body is disposed so as to link the divided sheet portions in parallel, the outer edge portions of the outer layer materials constituting the sheets are respectively folded, and the both edge portions of the absorbent body are fixed by the folded portions. Subsequently, the absorbent body is folded in the vicinity of the central portion and the sheets are superposed so that the inner layer material comes to the inside, and the sheets that are superposed so as to interpose the absorbent body therebetween are bonded at predetermined intervals in the lateral direction. Thereafter the central portion of the bonded portion is cut in the lateral direction of the sheets and the cut portions are separated off. By this way, a pull-on diaper comprising an outer cover formed by bonding sheets, and an absorbent body fixed on this outer cover is completed (for example, see Patent Literature 1).
Another disclosed structure comprises an integral outer cover sheet that covers from a front body to a rear body; band-like sheet materials extending in the lateral direction, which are plurally disposed in a staggered arrangement in the longitudinal direction on the outer surface of the outer cover sheet; and an elastic-stretchable element under waist that also acts as a gathered elastic-stretchable element, which is interposed into an edge portion on the waist side of the superposed portions of the band-like sheet substrates and outer cover sheet and fixed by a hot-melt adhesive or the like (for example, see Patent Literature 3). Since each edge portion on the crotch side in the CD direction (the lateral direction at right angles to the line flow direction) of the band-like sheet materials is disposed so as to cover another band-like sheet substrate whereunder, the outer cover sheet as a whole has a two-layer structure comprising at least the outer cover sheet and band-like sheet materials (the outer cover sheet has a three layer structure at the superposed portion of the band-like sheet materials). A method for producing this comprises continuously interposing the elongated elastic-stretchable element between the outer cover sheet and band-like sheet substrates, and, at the same time, fixing the elastic-stretchable element to the edge portions of the waist side of the band-like sheet substrates using a hot-melt adhesive. Therefore, it is necessary to dispose the respective band-like sheet materials in a staggered arrangement so that the respective band-like sheet substrates are partially overlapped, and thus the positional accuracy of the band-like sheet materials with respect to the elongated elastic-stretchable elements is important.